Well the gap is supposed to be there. The pulling on her shoulders may be how she is adjusting the straps. First thing to try: make sure the hip belt is tight enough. Then losen shoulder straps until the pack rest more on her hips. Let us know if that helps at all. It you can, send a picture including the hip belt placement as it will be easier to see what is going on.

The jam needs to be packed right, IMHO, in order to get the most out of it since its frame, if you want to call it that, is very wimpy. What sleeping pad is she using and how is it packed? The ideal kind of pad, also in my personal opinion is something like a ridge-rest (vest) or a zrest (next best) you should try to uses it if possible to support the pack as an extra "frame".

Assuming that the torso length isn't too long, I'll make a comment that seems to stir up a lot of negative comments from those that like to "make a frame" with their foam pads. I've personally never understood why you would want to make a frameless pack rigid with a foam pad as it defeats the benefits of using a frameless pack.

In your picture, the pack looks like a stiff board which suggests that it has been stiffened with a pad or frame sheet of some sort. This will often cause the pack to tip away from the shoulders and the user will cinch up the shoulder straps to try and bring the pack back closer to the shoulders (and cause shoulder pain from tight straps).

Try removing the frame sheet or foam pad and just fill the pack with your gear and then "shape" the pack to fit the curve of your girl friends back. I can make my frameless pack follow the contour of my back perfectly by bending it with my hands (or my knee if it's a tightly packed load). The key here is to pack the frameless pack with a fairly rigid load (but not rock hard) and shape the pack as needed for best fit.

Some people seem to like the "stiff board" effect that a foam pad creates when added as a frame, but I've never liked it. Give it a try without a foam frame sheet and shape the loaded pack to fit and see if it makes any difference.

Hmm...well if she's smaller than the 28" waist listed on golite's website (if that's accurate) for a medium Jam you probably won't find too much for waistbelts in a pack that small without a custom order. Osprey makes an extra small hipbelt but I think that fits their larger packs.

I am extremely skinny and have had many of the problems you have in finding a pack.For frameless pack for 1-2 days is the Hornet 46It is capable of reaching small waist sizes. I have have a 28" waist with 18" torso the S/M fits nicely.Also my 11 year old daughter wears it and loves it.

This was the smallest hip belt in a feature full pack I have found.It is short on padding but hugs the hips well. So 12-15 lbs is probably close to limit.

FWIW-If you want to get semi custom give Lawson Kline(Lawson Equipment) a call he is wanting some opportunities to test his designs. He posts here and you can see some of his work in past posts.He is going to make me a pack starting in Sept.